Oil and oil containing compounds occur naturally in the environment. Ground oil seepage exists in many parts of the world including the Gulf of Mexico and off the California coast. Additionally, to the extent that oil is transported in seagoing vessels or removed from the earth using offshore oil rigs, oil will periodically spill into the environment, specifically the seas and oceans. Oil does dissipate with time, and while the exact mechanism is not a number of factors are believed to contribute to the oil's apparent disappearance/environmental assimilation. As stated, the full mechanism or mechanisms by which oil is dissipated is an open question. A better understanding of how oil behaves in the sea may allow scientists to deal with the catastrophic effects of accidental or deliberate man made oil spills.
Oil in the environment can form micro-bubbles with relatively large surface to volume ratios, this may be especially so when surfactants are mixed the oil. These micro-bubbles form an emulsion in the seawater and can create significant underwater oil plumes. Some oil, by virtue of other mechanisms, composition and other factors form other sub-surface oil formations, both in the emulsion class and in other classes. These plumes can cover significant areas and can have serious consequences for animal and plant life which come in contact the plume.
Certain biological species are voracious consumers of the oil micro-bubbles which can be components in subsea oil plumes. Certain chemicals can likewise effectively reduce the deleterious impact that an oil plume has on plant and animal life. The first step in developing an effective response to oil spills, regardless of the cause, is knowing the extent and location of the undersea oil plumes. Present technology, including sonar and turbidity measurements are fraught with problems associated with false positives and false negatives resulting from other factors present in the seawater. In many cases samples have to be captured thousands of feet below the ocean's surface and physically taken to the ship where they can be investigated and characterized.
What is needed is an effective in situ system that effectively identifies areas of hydrocarbon contamination in seawater by depth, location, concentration, and composition. By composition it is understood that effective responses rely on knowing the characteristics of hydrocarbon, such as molecular weight and composition, which be meaningful and sometimes critical in preparing an effective response to a hydrocarbons based environmental incident as well as the environmental condition in which the hydrocarbon is present, such as local salinity profile, local sea water composition and presence, type and concentration of surfactants.
What is desperately needed is a robust system that can effectively determine both concentration of oil in seawater but also can provide valuable insights on the chemical properties of the oil, thus allowing for a more effective, more focused and less costly response, all of which can meaningfully preserve a delicate ecobalance and preserve the environment for generations to come. In addition, if it known where an oil plume is not, that information can allow officials to open areas that fisherman and others rely on for their livelihoods. Such areas might otherwise be closed to commercial fishers out of caution.